The invention of this application relates to the field of manufactured articles having the characteristics of natural articles. More particularly, this invention relates to methods and apparatus for producing a plastic article with some of the contours and colors of natural articles, and then employing a unique process to imbue the plastic article with corners, edges, and shapes not found in those natural articles, thereby creating a master part representing a state of the art previously unknown, and using this master part to manufacture plastic reproductions in commercial quantities.
Many people have attempted to manufacture plastic parts simulating the contours and colors of natural articles, but either produce an item that does not look authentic or that poorly reproduces the natural article in its entirety. One example is Formica(copyright), a hard plastic substrate used to cover countertops and the like. Some forms of Formica(copyright) were impregnated during manufacture with dyes or other colored material to simulate the look of wood or stone. But the simulation was not convincing because the Formica(copyright) was flat. It did not have the texture of the natural articles it purported to simulate.
Another example is Corian(copyright). This was made from plastic in the form of sheets of varying thickness for use as countertops and related structures. Most forms of Corian(copyright) were made by mixing filler materials with plastic. The resulting product was colored much like the filler material used during manufacture. Some forms of Corian(copyright) were made to resemble stone. But the simulation was not convincing because Coriane was largely flat. It did not have the texture of the natural articles it purported to simulate.
Yet another example is Linoleum(copyright). This was made from various plastics and fillers, and was sold in the form of sheets or rolls, principally for covering floors with a wear-resistant surface. While some forms of Linoleums were colored and textured to resemble natural articles, the simulation was not convincing. The colors were artificial and the texture so regular as to dispel the notion of a natural articles.
Still another example is plastic floor tiles. These were typically squares of regular size. They were intended to be butted against one another once a mastic had been applied, and some were both colored and textured to resemble natural articles. However, the colors were often unconvincing. And the same was true for the textures, which were not only shallow, but also discontinuous where one tile butted up against another.
Another example is exterior siding designed to replace or cover some or all of the exterior of outdoor structures, including houses. This siding typically was made of plastic or aluminum and was marked or embossed in an effort to simulate natural articles. But the simulation was not convincing. The colors were unconvincing and the textures were not only shallow and unrealistic, but also discontinuous where one piece of siding butted up against another.
Another example is cultured stone. This was cast from cement and aggregate and simply mimicked the characteristics of real stone. It could not be molded any differently from the natural article, and required the same methods for installation as real stone.
Processes for casting plastics are disclosed in U.S. Pat. No. 5,750,583 to Gansen et al. and U.S. Pat. No. 3,883 627 to Fitts. Gansen et al. disclosed a process for the preparation of polyurethane products in which a plastic film was positioned in a mold, the mold was closed, a polyurethane reaction mixture was injected into the mold, and the product was removed from the mold once the reaction mixture had fully reacted.
Fitts disclosed a process in which a heat curable elastomeric sheet comprising a curing agent and either urethane elastomeric gum stock or silicone gum stock was placed over a master to be copied; the heat curable elastomeric sheet was one that did not cause inhibition between the master and the heat curable elastomeric sheet. Next, the elastomeric sheet was vacuum drawn against the master and the master sheet material was enclosed in a frame. Next, a foamed polymeric backing was formed in situ to force the heat curable elastomeric sheet against the master to copy the shape of the master in the heat curable elastomeric sheet, which was then cured in the shape of the master. Finally, articles were molded in the shape of the master in a mold constructed from the cured elastomeric sheet material.
A decorative plastic moulding was disclosed in U.S. Pat. No. 5,372,869 to Drexinger et. al. The moulding comprised two moulding pieces, each with a decorative face, a back, two sides and two ends. Each end of each piece had a 45 degree angle pre-mitered cut relative to the plane of the decorative face, with the pre-mitered cuts of each piece being in parallel planes. Each side of each piece was in a plane at a 45 degree angle to the plane of the decorative face, with the side planes converging at a position spaced from the back of the piece. The two moulding pieces were made of fire rated polyurethane.
Finally, a method for molding an artificial rock was disclosed in U.S. Pat. No. 4,940,558 to Jarboe et. al. This method entailed selecting a rock for reproduction, creating a flexible rubber mold and supporting cradle having a mold cavity conforming to the exterior of said rock, the mold having a substantial degree of flexibility and being created by applying an uncured liquid rubber forming material to said rock, curing the uncured liquid rubber forming material to produce the rubber mold, the cradle being formed by applying by spraying a low density urethane foam forming mixture to the exterior of the rubber mold to provide a self-supporting cradle, spraying a two-sided urethane composition into the mold cavity, said urethane composition comprising an isocyanate side and a polyol side and being mixed in a spray gun in a spray-in-mold process, carrying out the spraying to build up the molded artificial rock to a desired thickness and stripping the cradle and mold after curing.
Generally speaking, the invention of this application comprises methods and apparatus for producing manufactured articles or reproductions with characteristics of natural articles. These reproductions can replicate the contours and colors of all or part of a natural article and can be made in any shape or size. Steps in making these reproductions include the production of a mold of the natural article, with or without modification. This is followed by production of a master reproduction from the mold, typically by casting. The master reproduction is used to form another mold from which commercial quantities of commercial reproductions can be made. These reproductions represent a state of the art previously unknown.
One method of the invention for making reproductions that replicate the surface of a natural article comprises the steps of modifying a natural article to a predetermined configuration, making a mold of at least part of the modified natural article, and filling the mold with a castable material to produce a reproduction of at least part of the surface of the modified natural article. Next, the reproduction is modified to a predetermined configuration to make a master reproduction. Finally, another mold is made from the master reproduction and this mold is filled with a castable material to produce another reproduction of at least part of the surface of the modified natural article. This second mold can be used to produce reproductions in commercial quantities.
Another method of the invention for making reproductions that replicate the surface of a natural article comprises the steps of making a mold of at least part of the surface of a natural article and then lining the inner surface of a support structure with the mold so that the surface of the mold that replicates the surface of the natural article faces away from the inner surface of the support structure. Next, the support structure is filled with a castable material to produce a master reproduction of the lined inner surface of the support structure. Finally, the master reproduction is placed into a second support structure shaped to receive the master reproduction and a mold is made of the master reproduction. This mold can be used to produce reproductions in commercial quantities.
Apparatus of the invention includes a system for continuous production of cast reproductions that replicate the surface of a natural article. This system comprises a conveyor, one or more molds positioned on the conveyor, each of which replicates on at least part of its surface the surface of a natural article, a dispenser positioned adjacent to the conveyor for filling one or more of the molds with a castable material, and another conveyor positioned adjacent to the first conveyor for confining castable material to the molds. This system can further comprise one or more dispensers of paint, powdered coloring agents, or solvent positioned adjacent to the first conveyor, as well as a heater for heating the molds and drying any paint, coloring agent or solvent placed in the mold.
Yet another method of the invention for continuous production of cast reproductions that replicate the surface of a natural article comprises the steps of placing on a conveyor at least one mold that replicates on at least part of its surface the surface of the natural article, conveying the mold to a dispenser of castable material, filling the mold from the dispenser with castable material, and confining the castable material to the mold. The latter step can be accomplished by use of a second conveyor positioned adjacent to the first conveyor.
These methods and apparatus can be practiced or configured in a number of variations. Molds can be placed in rigid support structures to facilitate casting of manufacture reproductions in commercial quantities. The rigid support structure can be made of metal, wood or the like and lined with an inert material to prevent adhesion of castable material to the rigid support structure.
A reproduction can be colored by placing a powdered coloring agent or a paint (or both) into a mold before the mold is filled with castable material. In another variation, a powdered coloring agent is mixed into the castable material before the mold is filled with the castable material.